In hydrocarbon exploration, accurately understanding the economic projections of a reservoir is vitally important. Conventional approaches include the use of reservoir simulators which predict production behavior and, hence, cashflow from a well. In addition to the reservoir simulators, however, geomechanical calculations are also required to account for the reduction in proppant permeability (i.e., proppant damage) over time—which directly effects production. In conventional reservoir simulators, to model this effect engineers utilize compaction tables, so called because they were developed to model compaction effects consisting of pressure versus transmissibility and pore volume relationships.
In conventional thought, laboratory tests and physical theory suggest that permeability in proppant packs is a function of closure stress and pore pressure. The disadvantage to this approach is that calculating closure stress and analyzing the laboratory-determined relationships between fracture permeability and closure stress directly would be too computationally demanding on the reservoir simulator, and would require more data than typically available. Therefore, it would be much more practical to develop a reservoir simulator which somehow utilizes the fracture permeability versus closure stress relationship in a computationally efficient manner. To date, however, no solution has been presented to the industry.
In view of the foregoing, there is a need in the art for a reservoir simulator that converts the fracture permeability versus closure stress relationship to a fracture permeability verses pore pressure relationship, and vice versa, in order to predict proppant damage on production, to thereby provide a more accurate economic projection of the reservoir.